NH4Al(SO4)2·12H2O-Na2SO4 eutectic-based phase change materials with excellent light absorbance, enhanced thermal conductivity, and high latent heat performance

Abstract

A novel eutectic phase change material with light absorption and high thermal conductivity was successfully prepared. The based phase change material was ammonium aluminum sulfate dodecahydrate‑sodium sulfate eutectic phase change materials. The black Ti2O3 after ball milling was selected as light thermal conversion material which can absorb sunlight effectively and simultaneously convert the light to thermal and the expanded graphite was added to further improve the thermal conductivity of phase change materials. The phase change temperature of the eutectic phase change material was effectively regulated to 80 °C compared with 93 °C of pure aluminum sulfate dodecahydrate. The thermal conductivity of eutectic phase change materials with expanded graphite was enhanced to 1.16 W·m−1·K−1 compared with 0.53 W·m−1·K−1 of the pure eutectic phase change material. By adding Ti2O3, the combination material shows the best solar absorbance capacity of 87.96 % compared with the pure eutectic phase change materials of 73.43 %. The latent heat of the novel material was 190.97 kJ/kg. Considering their huge superiority of highly efficient use of solar energy in natural resources, the new novel ammonium aluminum sulfate dodecahydrate‑sodium sulfate eutectic-based phase change material with excellent light absorbance, enhanced thermal conductivity, and high latent heat performance is a very promising material for solar-thermal conversion and energy storage.